Area of a Triangle

Area of a Triangle

In the past, to find the area of a triangle we have used the formula

A=(1/2)bh

where b=base h=height

But, if we do not know the height of a triangle, we can use trigonometry to help us determine the area

In order to find the area of a triangle using trigonometry, we need the 2 side lengths and the angle that lies in between the two sides

Then, we can use the formula

A=(1/2)ab*sin(C)

Why does this work?

A=(1/2)bh

Example:

Fill in the Blanks

Find the area of this triangle. Round to the nearest thousandths place.

Fill in the Blanks

Find the area of this triangle. Round to the nearest thousandths place.

Fill in the Blanks

Find the area of this triangle. Round to the nearest thousandths place.

Work on:

pg. 540 #4, 6, 7, 9